/*
*	ID : pallab81
* 	PROG : D_1
* 	LANG : C++
* 	2012-09-10-14.28.46 Monday
*
* 	"I have not failed, I have just found 10000 ways that won't work.
*/
#include <iostream>
#include <algorithm>
#include <vector>
#include <sstream>
#include <fstream>
#include <string>
#include <list>
#include <map>
#include <set>
#include <queue>
#include <deque>
#include <stack>
#include <functional>
#include <bitset>
#include <iomanip>

#include <ctime>
#include <cassert>
#include <cstdio>
#include <cmath>
#include <cstring>
#include <climits>
#include <cstring>
#include <cstdlib>

using namespace std;


#define foR(i1,st,ed) for(int i1 = st , j1 = ed ; i1 < j1 ; ++i1 )
#define fo(i1,ed) foR( i1 , 0 , ed )
#define foE(i1,st,ed) foR( i1, st, ed+1 )
#define foit(i, x) for (typeof((x).begin()) i = (x).begin(); i != (x).end(); i++)
#define bip system("pause")
#define Int long long
#define pb push_back
#define SZ(X) (int)(X).size()
#define LN(X) (int)(X).length()
#define mk make_pair
#define SET( ARRAY , VALUE ) memset( ARRAY , VALUE , sizeof(ARRAY) )
#define line puts("")

template<class T1>
inline void debug(T1 _x) {
    cout<<_x<<'\n';
}
template<class T1, class T2>
inline void debug(T1 _x,T2 _y) {
    cout<<_x<<' '<<_y<<'\n';
}
template<class T1, class T2, class T3>
inline void debug(T1 _x,T2 _y,T3 _z) {
    cout<<_x<<' '<<_y<<' '<<_z<<'\n';
}
template<class T1, class T2, class T3, class T4>
inline void debug(T1 _x,T2 _y,T3 _z,T4 _zz) {
    cout<<_x<<' '<<_y<<' '<<_z<<' '<<_zz<<'\n';
}
template< class T1>
inline void debug(T1 _array,int _size) {
    cout<<"[";
    for (int i=0; i<_size; ++i) {
        cout<<' '<<_array[i];
    }
    puts(" ]");
}
inline bool CI(int &_x) {
    return scanf("%d",&_x)==1;
}
inline bool CI(int &_x, int &_y) {
    return CI(_x)&&CI(_y) ;
}
inline bool CI(int &_x, int &_y, int &_z) {
    return CI(_x)&&CI(_y)&&CI(_z) ;
}
inline bool CI(int &_x, int &_y, int &_z, int &_zz) {
    return CI(_x)&&CI(_y)&&CI(_z)&&CI(_zz) ;
}
inline void wait( double seconds ) {
    double endtime = clock()+( seconds* CLOCKS_PER_SEC );
    while( clock() < endtime ) {
        ;
    }
}
#if !defined( ONLINE_JUDGE )
#define debug
#endif
char str[105];
char pat[105];
int l_str;
int l_pat;
int N;
int K;
int pi[105];
inline void prefix_function (char *s) {
    int n = strlen(s);
    SET(pi,0);
    for (int i=1; i<n; ++i) {
        int j = pi[i-1];
        while (j > 0 && s[i] != s[j]) {
            j = pi[j-1];
        }
        if (s[i] == s[j]) {
            ++j;
        }
        pi[i] = j;
    }
    return ;
}
int aut[105][30];
char s[105];
inline void kmp_autometa(char *ss) {
    SET(aut,0);
    sprintf(s,"%s{",ss);
    prefix_function(s);
    int n = strlen(s);
    for (int i=0; i<n; ++i) {
        for (char c='a'; c<='{'; ++c) {
            if (i > 0 && c != s[i]) {
                aut[i][c-'a'] = aut[pi[i-1]][c-'a'];
            } else {
                aut[i][c-'a'] = i + (c == s[i]);
            }
        }
    }
}
inline void read() {
    scanf("%d %d\n",&N,&K);
    gets(str);
    gets(pat);
    l_str= strlen(str);
    l_pat= strlen(pat);
}
bool dp[105][105];
bool vis[105][105];
bool go(int at, int prefix) {
    if( at>= l_str ) {
        int indx = at-l_str;
        if( pat[indx]=='0' && prefix==l_str )return false;
        if( pat[indx]=='1' && prefix!=l_str )return false;
    }

    if( at==N ) {
        return true;
    }
    if( vis[at][prefix])return dp[at][prefix];
    vis[at][prefix]=true;
    fo(i,K) {
        if( go(at+1, aut[ prefix ][ i ] ) ) {
            return dp[at][prefix]=true;
        }
    }
    return dp[at][prefix]=false;
}
inline void bk(int at, int prefix) {
    if( at>=N ) {
        return ;
    }
    fo(i,K) {
        if( go(at+1, aut[ prefix ][ i ] ) ) {
            putchar( (char)('a'+i) );
            bk(at+1, aut[prefix][i]);
            return ;
        }
    }
    return ;

}
inline void proc() {
//    puts(str);
//    puts(pat);
    kmp_autometa(str);
    SET(vis,false);
    bool f = go(0,0);
    if(!f) {
        puts("No solution");
    } else {
        bk(0,0);
        line;
    }
}
int main() {
    int kase=1;
#if !defined ( ONLINE_JUDGE )
    freopen("in","r",stdin);
    kase=1;
#endif
    fo(i,kase) {
        read();
        proc();
    }
    return 0;
}


